/Engine/Source/Runtime/Experimental/ChaosCore/Public/Chaos/Vector.h
This is used as
namespace Chaos { template<typename T, int d> [FArchive](API\Runtime\Core\Serialization\FArchive) & Chaos::SerializeReal ( [FArchive](API\Runtime\Core\Serialization\FArchive) & Ar, [TVector](API\Runtime\Chaos\Chaos\TVector)< T, d > & ValueIn ) }